This invention relates to the treatment of sewage. More particularly, this invention relates to the treatment of sewage discharged from houses and other buildings which are not connected to a municipal sewer system such that, after the sewage has passed through the three stage sewage treatment system (TSSTS), it has been cleaned to a level acceptable for discharge into the environment so that it will not contaminate the ground water. Thus, the TSSTS provides an alternative to septic systems for buildings constructed outside of a local municipal sewer system.
There are several versions of the conventional sewage treatment system which use aerobic microorganisms to break down sewage. One such device is seen in U.S. Pat. No. 5,549,818. This conventional sewage treatment device consists of a cylindrical tank which encompasses a funnel-shaped clarifier. Thus, the cylindrical tank is divided into an outer chamber, between the outer wall of the tank and the clarifier, and an inner chamber, inside the clarifier. Air is introduced into the outer chamber by multiple air droplines, which are connected to an air compressor and which pump air bubbles into the sewage in the outer chamber. Sewage flows into the outer chamber where it comes in contact with the air bubbles. The introduction of air facilitates the breakdown and digestion of the sewage by aerobic microorganisms present in the sewage. The aerated sewage then proceeds into the clarifier through an opening at the bottom of the funnel-shaped clarifier. Inside the clarifier is a quiescent zone. This area of calm in the inner chamber of the device allows for settling to occur, with the solids falling back out of the clarifier and collecting on the bottom of the treatment tank. Accordingly, the waste water becomes cleaner as it progresses upward in the funnel-shaped clarifier, continuing to allow gravity to separate the solids from the water. So, by the time the sewage has progressed up through the clarifier, it has been substantially cleaned. This treated effluent exits near the top of the clarifier and is discharged.
The Three Stage Sewage Treatment System (TSSTS) employs a more comprehensive three step process to clean sewage. Thus, it is able to treat sewage more thoroughly than conventional devices while still offering a single, simple-to-install unit for this complete processing of sewage, The sewage first enters a pretreatment area. It then proceeds to an aeration chamber followed by a settling chamber in a clarifier. Finally, the sewage enters a post-treatment area, where it is chlorinated before discharge. Through this multi-step process, the TSSTS produces a cleaner effluent.